1. Field of the Invention
This invention relates to a portable electronic token and in particular it relates to a portable token of credit card sized dimensions and containing electronic circuits for data storage and processing. Such a token is commonly termed a "Smart Card" or "integrated circuit card". The term "token" as used herein is to be understood to include "card".
2. Background Information
A Smart Card generally comprises one or more components such as integrated circuits mounted on a substrate and encapsulated within a plastics material or laminate of credit card sized dimensions, typically 8.5.times.5.4.times.0.075 cms. It is important that such cards are flexible so that they can be placed in the user's pocket, wallet or purse and be capable of withstanding bending forces. Furthermore, for the card to be compatible with present day systems it must include a magnetic strip and meet with the flexing requirements imposed upon cards to be used in cash dispensing machines, which are governed by ISO standards.
It has been previously proposed to provide a contact-type smart card structure which protects the components, either by mounting them on a metal foil and encapsulating them in a hard resin as described in EP0068539A, or by providing a box-like structure of a plastics material within the token which encloses the components as described in U.S. Pat. No. 4,755,661.
The present invention seeks to provide an alternative structure which is particularly applicable to contactless smart cards.